Red hair going extinct???

By Razib Khan | August 25, 2007 12:29 am

nicole%20kidman%20helicopter.jpgEvery few years it seems that a new meme declares that “blondes will go extinct!” or that “red hair will go extinct!” I’ve only been blogging for 5 years, and this story has already cycled multiple times. A co-blogger of mine told me that he did some digging and it seems that this meme is of old vintage, with “blondes going extinct!” stories dating back to the 19th century. The current craze (as evidenced by blogs) seems to have started at an Australian newspaper. But, it is sourced originally to National Geographic Magazine.
First, the story doesn’t appear on National Geographic Magazine’s website that I can tell. Perhaps it is in the print issue? A reader who has a copy of the current issue might want to post their finding in the comments (I will probably go the bookstore tomorrow and check myself). Let’s assume that the story is correct. What are they actually trying to say here? They are actually just restating inferences derived from the Hardy-Weinberg Equilibrium in a panmictic population; this isn’t really a “discovery.” Let me clarify what I mean.

  1. Red hair seems to be correlated in large part with two loss of function mutations on the MC1R locus.
  2. This means that to a first approximation one can conceive of it is a recessive Mendelian trait.
  3. A population in Hardy-Weinberg Equilibrium (HWE) is governed by the relation: p2 + 2pq + q2 = 1, assuming a diaellelic locus where random mating, migration, mutation, selection and drift are not operative dynamics.

If one assumes that q2 represents the proportion which is homozygous for an allele which only expresses when within that genotype, then one can intuit in HWE as the frequency of q decreases a greater and greater proportion of that allele will be found paired with the p allele (since p is simply the balance left over from the proportion of q). The stories commonly report that only 1-2% of the world’s population are redheads currently, so one can imagine that q is already extant at low frequencies. In reality it seems that more than one allele results in loss of function, but in terms of phenotypic effect they are equivalent.
Since the frequency of these alleles differ by population there is a strong deviation from random mating; e.g., the typical Scot marries another Scot, who are already likely to have a much greater chance of carrying the loss of function allele than a non-Scot. As intermarriage across nationality’s occurs the proportion of loss of function alleles masked in heterozygote states should increase, so the realized proportion of the redhair phenotype will approach q2 in direction proportion to how close to random mating we are. I am very skeptical that the National Geographic Magazine article, if it exists, presented a detailed demographic model so that one could posit that red hair became “extinct” at a particular date. In fact, I strongly suspect that anyone who says that red hair (or blonde hair) is going extinct is in need of a few envelopes or napkins to do some basic algebra, or at least stipulate what low proportion is “close enough” for them to consider a trait “extinct.” Finally, as I noted last year, part of the appeal of the stories is probably the disquiet of white people at the “passing of the great race.” The reality is that I don’t think that the white race is going away anytime soon, but surely a non-trivial proportion of whites are concerned at some level that the colored folk are swallowing them up, and the blonde and red hair stories are simply subtle manifestations of that. These traits are after all amongst the most distinctive of the northern European peoples, and so they can be emblematic of the threat posed by declining birth rates and miscegenation.
Addendum: For regular readers, I am aware that the technical exposition was retarded. That’s for Google, not for you my wise souls!

CATEGORIZED UNDER: Genetics
  • Jeb, FCD

    Oh I hope not!
    Redheads are the cherry atop the sundae of life.

  • _Arthur

    Assuming theres a strong propension to mate with blondes, *blondes* will be likewise attracted to blondes, bridding new blonds, so there will still be bondes.
    Also, the more there are non-blondes pairing with blondes, the more there are recessive blondes, leading to more non-blond couples having blond kids.
    So no, blondes are extremely unlikely to become “extinct”.

  • knobody

    as long as there is hair dye, redhead will not be extinct.

  • Scotty B

    In the long run we’re all going extinct, right? ;)

  • http://www.scienceblogs.com/thusspakezuska Zuska

    This kind of shit is so depressing. Thanks for posting on this. You are soooooo right…all that anxiety about blonds and redheads disappearing is really a mask for racial anxiety, fear of the colored folk. I’m not surprised that stuff like this is resurfacing now with all the anti-immigration fever we have going on.

  • http://360.yahoo.com/thefolksbackhome SM Higginbotham

    The article is a one page item in the
    September 2007 Nat Geo titled Red Alert. It is on page 20. I do not think it is on the website, or if it is I was unable to locate it.

  • http://www.selectiveamnesia.org Ravages

    Heh! What next? Brown skin turning white? (Perhaps due to migration, climate change?)
    LOL @ teh last line.

  • Amanda

    This was a great post to read, and I am glad to have stumbled upon it in browsing the web. Genetics always fascinate me, though in no way do I profess any mastery in the field.
    It was interesting your comment on blondes (heterozygous for red-heads and vice-versa if I understand genetics properly) where it concerns a fear that the caucasian is “dying out” or being “overtaken”. I happened upon a mapping of the United States someone had created for whatever purpose, displayed the spreading of non-caucasians, and had been published in a pretty popular media if memory serves. Personally I have no feelings as it regards this matter, but I have never seen these two matters drawn together before reading this blog.

  • Winfred Mann

    You can put this up there with global warming.

  • Angie

    Im a redhead myself. If what you say it right about this dating all the way back to the 19th century, redheads and blondes will never go extinct. hundreds and thousands of babies are born each day with either brunette, blonde or red hair. Hello People! WE ARE IN THE 21st CENTURY!!! 3 CENTURIES AGO! come ON! This is just nonsense.

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Gene Expression

This blog is about evolution, genetics, genomics and their interstices. Please beware that comments are aggressively moderated. Uncivil or churlish comments will likely get you banned immediately, so make any contribution count!

About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at http://www.razib.com

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